Hi,
I just checked my engine. The main needle is set at just 1 and a (little) bit turns out from closed.
I have never touched the slow speed screw as it was O.K.

If you have altered the slow speed setting then just ignore it untill you get the engine running at full throttle, you can then set up the idle speed and check transition.

I am using 10% nitro fuel and I find the needle setting doesn't have much leeway. I find that 3 clicks will be about as much as you can go before the carb starts going lean or rich and the engine threatens to quit.

I see you fitted a new needle. I reckon once you get the correct needle setting all will be well. I have not encountered a carb as sensitive as this, a couple of clicks either side of the ideal position and the engine will indicate it is not happy ! My other, bit bigger, engines all have a broader range of needle setting with 10% nitro and are nowhere near as sensitive as the 07 is.

As stated by someone else... the engine is not a power house, but it does run very nicely and also reliably when you get a few tanks of fuel through it.

I seem to remember I had to quickly alter the needle to keep it running after I managed to get it started as it would do the same as your's... cut out quite quickly.

Good luck

Reg

p.s. I would not use this engine without a fuel filter in line. It would be veryy easy to get a blockage .